Biomedical subjects

T Böker

Publications and source records attributed to T Böker.

At least 19 recordsLinked to original sources

PubMed2000

[Smoking cessation practice among Norwegian hospital physicians].

BACKGROUND: Limited data is available as to what extent Norwegian hospital doctors ask their patients about their smoking habits, and to what extent doctors offer their patients help in smoking cessation. MATERIAL AND METHODS: A random sample of 1,025 hospital doctors was mailed a questionnaire. After 14 days a reminder letter was sent to non-responders; 76% of the doctors responded. RESULTS: Altogether 98% of the doctors stated that they asked their patients with smoking-related disease about their smoking habits. In cases of non-smoking related disease, 73% of the doctors stated that they asked about the smoking habits of their patients (83% of female and 69% of male doctors). If doctors knew that a patient wanted to quit smoking, 25% of them stated that they often recommended nicotine replacement therapy. Less than 7% of the doctors regularly offered smoking cessation courses, handed out self-assistant material, or gave the patients other smoking cessation advice. INTERPRETATION: The study indicates that doctors often ask their patients about their smoking habits, but there is clear potential for improvement as to the smoking cessation advice.

Adult↗

PubMed2000

Long-term results of pneumatic retinopexy.

PURPOSE: To evaluate the long-term outcome (>6 years) of retinal reattachment by pneumatic retinopexy. METHODS: Seventy-eight eyes were examined retrospectively after treatment of a retinal detachment with pneumatic retinopexy. The average follow-up period was 6.35 years. The fundus was examined and visual acuity was documented and compared to that of the fellow eye. Any reoperations were evaluated. RESULTS: In 98.7% of cases permanent reattachment of the retina was achieved. In 85.9% the primary intervention had been successful. However, the retina redetached in 19.4% of these during the first 3 months and in a further 4.5% later during the observation period, requiring reoperation. The average number of operations necessary to obtain permanent reattachment of the retina in the 77 eyes was 1.39. One eye was lost due to phthisis bulbi and had to be enucleated. Six years after the first intervention visual acuity of the eyes without reoperation was 0.57 (+/-0.25 SD) with initially detached macula [fellow eye 0.67 (+/-0.27)] and 0.7 (+/-0.27) with attached macula [fellow eye 0.7 (+/-0.25)]. Visual acuity of the eyes with reoperation was 0.36 (+/-0.3) [fellow eye 0.51 (+/-0.29)] with initially detached macula and 0.64 (+/-0.26) [fellow eye 0.63 (+/-0.35)] with attached macula. CONCLUSION: Six years after initial pneumatic retinopexy the retina was found to be attached in 98.7% of eyes. In 65.4% this result had been achieved by minimally invasive primary surgery alone. The need for reoperation was evident during the first 3 months in 89% of the cases. The final visual outcome was satisfactory overall.

Adult↗

PubMed2000

Vannella sp. harboring Microsporidia-like organisms isolated from the contact lens and inflamed eye of a female keratitis patient.

Viable Hartmannella sp. and two strains of Vannella sp.--but no Acanthamoebae--multiplied on NN-agar inoculated with pieces of the contact lens from a female keratitis patient. Within the cytoplasm of one Vannella isolate, intracellular parasites could be observed whose earliest stages were developing within the nucleus, resembling those Microsporidia-like parasites seen within Vannella isolated recently from a warm tapwater system. This assumption was also confirmed by electron microscopy. In swabs taken directly from the cornea, Pseudomonas aeruginosa were identified, but they did not yield any growth of amebas in culture. However, cocultivation of parasite-free Vannella strains with the above-mentioned swab matter resulted in infected amebas harboring the same intracellular parasites seen before. This infection could be established only if the corresponding spores were present as infective agents in the swab matter. The successful treatment of the patient with antibiotics supports the assumption that P. aeruginosa was the main cause of the corneal ulceration. The extent to which the Microsporidia-like organisms may have been involved in the development of keratitis remains a matter of discussion.

Adult↗

PubMed2000

Induced corneal astigmatism using an asymmetric corneoscleral tunnel and a large-optic intraocular lens.

PURPOSE: To prospectively evaluate the induction of corneal astigmatism using an asymmetric corneoscleral tunnel incision (J-incision) to implant large-optic (7.0 mm) intraocular lenses (IOLs). SETTING: Department of Ophthalmology, University of Bonn, Germany. METHODS: Thirty-five patients had sutureless phacoemulsification with implantation of a 7.0 mm poly(methyl methacrylate) posterior chamber IOL using an inverse J-shaped asymmetric tunnel incision. The corneal astigmatism was measured by corneal keratometry and topography preoperatively and 1 day and 1 and 3 months postoperatively. Induced astigmatism was calculated by vector analysis. RESULTS: Mean induced changes in the corneal radii measured by keratometry were 0.17 mm +/- 0.14 (SD) on the first postoperative day, 0.18 +/- 0.14 mm after 1 month, and 0.17 +/- 0.14 mm after 3 months. Mean postoperative induced astigmatism measured by corneal topography was 1.08 +/- 0.66 diopters (D), 0.89 +/- 0.78 D, and 0.85 +/- 0.70 D, respectively. No signs of wound instability were detected. CONCLUSION: An asymmetric corneoscleral incision was suitable for implantation of large-optic IOLs, resulting in immediate stability of the induced cylindrical power in the central 3.0 mm zone as measured by keratometry. A reduction in induced corneal astigmatism can be achieved using this technique versus using symmetrical wound constructions and large-optic IOLs.

Aged↗

PubMed1999

Dacryoliths: nonsurgical fluoroscopically guided treatment during dacryocystoplasty.

PURPOSE: To evaluate dacryocystoplasty with fluoroscopically guided nonsurgical removal of dacryoliths in the treatment of dacryolithiasis. MATERIALS AND METHODS: Ten patients with severe epiphora due to partial (n = 8) or complete (n = 2) obstruction of the nasolacrimal duct system associated with dacryolithiasis underwent fluoroscopically guided removal of dacryoliths during dacryocystoplasty. Balloon dilation was performed initially to widen the nasolacrimal duct obstructions and to fragment dacryoliths. This was followed by forced irrigation with saline solution through the canaliculi. In patients with incomplete dacryolith washout, a 6.3-F sheath was advanced in a retrograde fashion into the nasolacrimal sac, and forced irrigation was repeated with aspiration of the fragments through the sheath. In two patients with therapy-resistant dacryoliths, additional fragmentation of the concrements was performed with a gooseneck snare. RESULTS: Removal of dacryoliths was technically successful in all patients (complete removal, n = 6; partial removal, n = 4). During a follow-up period of up to 18 months, complete resolution of epiphora was achieved in five patients, and five patients showed partial resolution of their symptoms. CONCLUSION: Fluoroscopically guided removal of dacryoliths during dacryocystoplasty is a feasible nonsurgical therapy with good clinical results and may be used as an alternative to dacryocystorhinostomy.

Calculi↗

PubMed1997

Complications of misdiagnosed and inadequately treated necrotizing scleritis studied by ultrasound biomicroscopy and computerized corneal topography.

We present a case of misdiagnosed and inadequately treated necrotizing scleritis leading to ocular complications. Scleral thinning and a marked secondary corneal astigmatism were observed and measured by ultrasound biomicroscopy and corneal topography. The purpose of this case report is to demonstrate the clinical value of additional diagnostic tools, such as ultrasound biomicroscopy and corneal topography and to alert ophthalmologists as to the complications of necrotizing scleritis.

Astigmatism↗

PubMed1997

[Stent implantation and balloon dilatation in the treatment of stenosis and obstruction of the lacrimal apparatus].

PURPOSE: To evaluate treatment of epiphora caused by obstructions of the nasolacrimal duct system with balloon dilatation and stent implantation. MATERIAL AND METHODS: 28 dacryocystoplasties were performed in 20 patients with complete (n = 7) or incomplete (n = 13) obstruction of the nasolacrimal duct system. RESULTS: Dacryocystoplasty was technically successful performed in 26 cases (93%). Recanalisation was not achieved in two patients with complete obstructions. 17 patients showed complete or partial resolution of epiphora during follow-up of up to two years (clinical success 85%). Complete reobstruction occurred only in one patient 9 months after balloon dilatation and recanalisation was not possible. CONCLUSION: With a technical success rate of 93% and a clinical success rate of 85% dacryocystoplasty is a non-operative alternative for treatment of epiphora caused by obstructions of the nasolacrimal duct system.

Adult↗

PubMed1996

Influence of oxygen free radicals and free radical scavengers on the growth behaviour and oxidative tissue damage of bovine retinal pigment epithelium cells in vitro.

PURPOSE: This investigation was carried out to ascertain whether oxygen free radicals can influence the growth behaviour and consecutive lipid peroxidation of retinal pigment epithelium (RPE) cells in vitro and whether scavengers can counteract these effects. METHODS: The experimental model was based on calf RPE cells. Hypoxanthine/xanthine oxidase (HX/XO) and superoxide dismutase/ catalase (SOD/CAT) served as the radical generating system and scavengers, respectively. The components were tested alone and in combination. Lipid peroxides were determined in culture supernatants by a thiobarbituric acid assay. RESULTS: Concentrations of up to 100 mumol/l of HX alone and 500/ 1000 microU of XO alone, as well as the application of the scavengers without the radical generating system (HX/XO), had no effect. Dose-related reduction of cell growth and increase of lipid peroxidation were found with HX/XO treatment (single dose of 500 and 1000 microU/ml 24 h after seeding). After application of 500 or 1000 microU/ml of XO, CAT, when given alone (1200 U/ ml), counteracted the effect of the radicals on cell growth and lipid peroxidation; SOD (300 U/ml) had no effect. A combination of SOD and CAT was no better than the effect of CAT alone. CONCLUSION: The prevention of radical-induced reduction of cell growth and lipid peroxidation by scavengers supports trials of therapy using antioxidants and/or free radical scavengers for various ocular syndromes with RPE involvement.

Animals↗

PubMed1996

Familial adenomatous polyposis: a submicroscopic deletion at the APC locus in a family with mentally normal patients.

Cytogenetically visible deletions that include the adenomatosis polyposis coli (APC) locus have repeatedly been reported in mentally handicapped polyposis patients. We report on a family with a submicroscopic deletion of about 200 kb including more than the 3' half of the APC gene and the adjacent DP1 gene. The deletion was detected by linkage analysis with flanking and intragenic markers and proven by in situ hybridisation with intragenic cosmid clones. All the familial adenomatous polyposis (FAP) patients and persons at risk in the family show normal behaviour and intelligence. Thus, it is conceivable that at least some of the FAP patients in whom mutations could not be identified by routine methods may have large but submicroscopic deletions.

Adenomatous Polyposis Coli↗

PubMed1996

Platelet factor 4 release in patients undergoing cardiopulmonary resuscitation--can reperfusion be impaired by platelet activation?

BACKGROUND: Reperfusion following cardiac arrest is associated with a marked activation of blood coagulation. This seems to be associated with microcirculatory reperfusion disorders. The present study was designed to investigate the possible involvement of platelets in reperfusion injury following cardiac arrest. Plasma levels of platelet factor 4 (PF 4) were used as an indicator for in vivo platelet activation because PF 4 is known to be released from platelets during aggregation. METHODS: Plasma PF 4 levels (normal range: < 5IU/mL) were measured in 18 patients at predetermined time points during cardiopulmonary resuscitation (CPR). In the case of restoration of spontaneous circulation, additional blood samples were analyzed until seven days after stabilization. The PF 4 levels of four sex-matched volunteers were used as controls. RESULTS: The median of the maximum individual PF 4 levels measured during CPR was 27.5 IU/mL (range 1.2 to 90 IU/ liter; P < 0.01 versus controls). Compared with PF4 levels in control volunteers (median: 0.35 IU/mL; range 0.2 to 0.6 IU/ liter), PF 4 levels were significantly elevated in patients during CPR and in the early phase until 24 hours after restoration of spontaneous circulation (P < 0.05). CONCLUSION: A marked increase in PF 4 levels was observed during CPR and in the early phase after cardiac arrest in man. This increase in PF 4 levels has to be viewed as an indicator of platelet activation, which may play a role in the etiology of reperfusion injury and microcirculatory reperfusion disorders occurring after cardiac arrest.

Aged↗

PubMed1995

Activation of blood coagulation after cardiac arrest is not balanced adequately by activation of endogenous fibrinolysis.

BACKGROUND: Animal studies have demonstrated that hemostatic disorders occurring after cardiac arrest affect outcome. We investigated hemostatic changes during and after cardiopulmonary resuscitation (CPR) in humans. METHODS AND RESULTS: The prospective study included 23 patients (29 to 86 years) who underwent out-of-hospital CPR for nontraumatic causes. Blood samples were drawn immediately and 15 and 30 minutes after initiation of CPR. In the case of restoration of spontaneous circulation (ROSC; n = 7), additional blood samples were taken immediately, 30 minutes, and 2, 8, 24, 48, and 72 hours after ROSC. A marked activation of blood coagulation was found in all patients. The specific markers of activated blood coagulation and fibrin formation, thrombin-antithrombin complex (TAT; median during CPR, 260 micrograms/L; median after ROSC, 57 micrograms/L; normal range, 1.0 to 4.1 micrograms/L), and fibrin monomers (FM; median during CPR, 34.3 micrograms/mL; median after ROSC, 65.4 micrograms/mL; normal range, 0 to 3.6 micrograms/mL) were markedly increased during and in the early phase after CPR. When patients survived for 48 hours, TAT and FM values returned to the normal range. In most patients, the plasma levels of D-dimer, an indicator of endogenous fibrinolytic activity, were not markedly increased during CPR (median, < 0.25 microgram/mL; normal range, < 0.25 microgram/mL) but increased moderately after ROSC (median, 0.56 microgram/mL). Levels of plasminogen activator inhibitor type 1 (normal range, 0.3 to 3.5 U/mL), a marker for endogenous inhibition of fibrinolytic activity, were moderately increased in most patients (median during CPR, 4.22 U/mL; median after ROSC, 8.08 U/mL). CONCLUSIONS: Our data clearly demonstrate that there is a marked activation of blood coagulation and fibrin formation after prolonged cardiac arrest and CPR in humans that is not balanced adequately by concomitant activation of endogenous fibrinolysis. These changes may contribute to reperfusion disorders, such as the cerebral "no-reflow" phenomenon, by inducing fibrin deposition and formation of microthrombi.

Adult↗

PubMed1995

Local effects of different perfluorochemical agents.

PURPOSE: To clarify whether the prolonged presence of perfluorochemicals (PFC) in the vitreous cavity causes oxidative tissue damage and inflammatory response of the retina and, if so, what the process is. METHODS: After three different perfluorochemicals [perfluorodecalin (C10F18), perfluorooctane (C8F18) and Fluosol-DA (corresponding to a 20% emulsion of 70% PFD and 30% perfluorotripropylamine, C9F21N)] had been in the vitreous cavity of rabbits for 2 weeks, lipid peroxide concentration and myeloperoxidase activity in the retina were determined. RESULTS: Whereas only Fluosol-DA showed significant oxidative damage, the inflammatory activity was significantly increased in all groups. CONCLUSION: The increased myeloperoxidase activity and the observed oxidative damage of the retina seem to be the effect of both perfluorochemical-loaded macrophages and inflammatory-induced lipid peroxidation.

Animals↗

PubMed1995

Systemic effects of different perfluorochemical agents.

PURPOSE: An intravitreal injection of Fluosol-DA leads to a higher alteration of the macrophage system of the retina than perfluorooctane and perfluorodecalin administered by the same route. The difference may be due to different kinds of oxidative damage caused by the three chemicals. To test the validity of this assumption, the degree of cell alteration, expressed as reduction of cytoplasmic motility, caused by these three perfluorochemicals was examined. METHODS: Using the hepatic macrophage system of the rat, cell alteration was examined by magnetometry after intravenous application of various perfluorochemicals [emulsified perfluorodecalin (C10F18), perfluorooctane (C8F17Br) and Fluosol-DA (corresponding to a 20% emulsion of 70% perfluorodecalin and 30% perfluorotripropylamine, C9F21N)]. RESULTS: After administration of high doses, all perfluorochemicals led to cytoskeleton alteration. This alteration, expressed as retardation of the relaxation period of ferromagnetic iron oxide particles, was most pronounced after administration of Fluosol-DA. CONCLUSION: The compromising effect of perfluorochemicals is dose dependent and differs among the three compounds tested, with Fluosol-DA showing the greatest decrease in cytoplasmic motility.

Animals↗

PubMed1995

[Larger sclerotomies for use of the multiport illumination system do not increase the complication risk of vitrectomy].

PURPOSE: To free both of the surgeon's hands for bimanual work in the vitreous cavity, Koch and coworkers developed the multiport illumination system, which, however, requires enlarged sclerotomies. PATIENTS AND METHODS: To evaluate the safety of the multiport illumination system we analyzed the first postoperative year of those 104 vitrectomies, that were performed using this system between January and December 1991. It was used only for patients suffering from advanced vitreoretinal changes that most likely require bimanual surgery. RESULTS: No specific intraoperative or postoperative complications were encountered that might possibly have been caused by the multiport illumination system. Postoperative fibrinous reactions were noted in the vitreous cavity of 7 patients, and in the anterior chamber of 15 patients. Rebleeding was observed in a total of 17 patients. CONCLUSION: When these complications were compared to data from other retrospective studies of vitrectomy and its complications, the multiport illumination, system was found to be as safe as conventional devices.

Diabetic Retinopathy↗

PubMed1995

Familial adenomatous polyposis: desmoid tumours and lack of ophthalmic lesions (CHRPE) associated with APC mutations beyond codon 1444.

An earlier study has shown that FAP patients with mutations in codons 136-302 of the APC gene do not develop congenital hypertrophy of the retinal pigment epithelium (CHRPE), whereas those with mutations in codons 463-1387 regularly do. Here we present data on 36 patients from 20 families with mutations in codons 1445-1578. These patients lack CHRPE. Furthermore, with the exception of three prepubertal children all patients with mutations in codons 1445-1578 developed desmoid tumours. This relationship between certain extracolonic manifestations and site of the APC mutation points to a specific role of the APC protein in different tissues.

Adenomatous Polyposis Coli↗

PubMed1995

Anterior chamber angle biometry: a comparison of Scheimpflug photography and ultrasound biomicroscopy.

Scheimpflug photography and ultrasound biomicroscopy allow measurement of anterior chamber angle width. To analyze the value of both diagnostic tools, measurements of the same subjects were correlated. Anterior chamber angle width in both eyes of 20 volunteers without any ophthalmological case history was measured in eight meridians. Scheimpflug photographs were recorded on Kodak T-max 400 black-and-white film using a Topcon SL-45 camera. Measurement of chamber angle was done with the aid of a self-programmed PC software. Ultrasound biomicroscopic measurements were obtained using a Humphrey UBM 840 system with a 50-MHz transducer. The chamber angle was measured as described by Pavlin et al. The data of both methods were correlated and analysed for statistically significant differences using a paired t test (level of significance p < or = 0.05). Both methods showed similar changes in chamber angle width and were able to document a variation in angle width with regard to location. The correlation averaged at 0.64. In 4 meridians significant differences were found between the two methods. Scheimpflug photography, however, is unable to visualize directly the angle itself. Both methods are limited by the fact that the angle is defined by curvilinear structures, i.e. posterior corneal surface and anterior iris surface. Scheimpflug photography is able to document changes in angle configuration. Ultrasound biomicroscopy, however, is a more precise method, because it allows direct documentation of all structures involved in chamber angle configuration.

Anterior Chamber↗

PubMed1995

Macular damage following lightning strikes.

Two men with recent history of lightining strike were referred to our hospital. Both patients complained of metamorphosia in one eye and reduced visual acuity. Funduscopy revealed target-like alterations at the fovea. Fluorescein angiography showed window defects of the central retinal pigment epithelium in both patients. One patient developed an anterior subcapsular cataract. If the eye is part of the current-circuit, the melanin granules of the iris, pigment epithelium, and choroid might act as a resistor. The resulting accumulation of heat may lead to damage of the surrounding tissues.

Adult↗

PubMed1995

Indicators of oxidative tissue damage and inflammatory activity in epiretinal membranes of proliferative diabetic retinopathy, proliferative vitreoretinopathy and macular pucker.

PURPOSE: To evaluate whether oxidative tissue damage and inflammatory reactions occur in epiretinal membranes of eyes suffering from proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and macular pucker (MP). METHODS: Epiretinal membranes were removed during surgery and frozen at -80 degrees C (PDR, n = 26; PVR, n = 24; MP, n = 15), and oxidative tissue damage and inflammatory activity (MPO) of the membrane tissue were determined. The values are expressed as means of thiobarbituric acid-reactive substances (TBARS, nmol/mg) and MPO (units/mg). RESULTS: Both TBARS and MPO activity were significantly elevated (P < 0.05) in membranes of eyes suffering from PVR and PDR compared to MP. The myeloperoxidase activity in PDR membranes was significantly increased (P < 0.05) compared to PVR. CONCLUSIONS: Inflammatory cells and oxidative metabolites lead to oxidative reactions in PDR and PVR. The proliferation of membrane tissue may be enhanced through products of the lipoxygenase pathway, which is active in inflammatory cells and leads to oxidative tissue damage. Chemoattraction of leukocytes by oxidative metabolites renders the process self-progagating. Since patients suffering from MP have an intact vitreous body with an intact antioxidative system, this reaction occurs to a lesser degree, resulting in less membrane-growth activity. The cell-growth-enhancing properties of inflammatory cells should be further investigated in PDR and PVR with regard to new therapeutic interventions.

Cell Membrane↗